wintertime scene

Have you had your vitamin D level checked lately? Chances are good that it has dropped since last summer.

Unless you are taking a supplement, most of your vitamin D is made by your skin when it is exposed to sunlight. Winter sun is too weak to do the job, even if you could stand to expose enough skin in the frigid air.

A surprisingly high proportion of people become deficient in vitamin D at this time of year. A recent study of pregnant women demonstrated that vitamin D blood levels (25-hydroxyvitamin D) peaked in the summer and dropped in the winter (Paediatric and Perinatal Epidemiology, online, Dec. 20, 2013).

Why might this matter? Over the past several decades, researchers have discovered that vitamin D is important for more than building strong bones. Virtually every cell depends upon vitamin D for normal functioning.

According to studies, this nutrient enhances the immune system and is critical for normal cell division. That’s why people deficient in vitamin D may be more susceptible to cancer, infections (including influenza), and autoimmune conditions such as arthritis, diabetes and multiple sclerosis.

Common conditions such as heart disease and high blood pressure may also be related to poor vitamin D status (Archives of Toxicology, Dec. 2013). It is less clear, however, that taking vitamin D supplements will reverse the damage.

Grandmothers in cold climates have had an empirical way to deal with low vitamin D during winter. They have been administering cod liver oil to their family members for centuries.

Traditional cod liver oil tasted and smelled awful. Children who were dosed with it remember this as torture even when they reach a ripe old age. Nevertheless, this winter tonic was an excellent source of vitamin D and vitamin A at a time when these nutrients were in short supply.

Today, doctors are debating how much vitamin D people need and what is the optimal blood level. There may be some individual variability in how well people utilize supplemental vitamin D, so it might make sense to add enough so that 25-hydroxyvitamin D reaches an appropriate level. There are details about the benefits of vitamin D and how much to take, along with the differences between D2 and D3, in our Guide to Vitamin D Deficiency.

We recently heard from a physician who was having trouble with shoulder arthritis. Out of curiosity, he had his vitamin D level measured and discovered that it was quite low. After he started taking supplements to bring the level back to normal, the pain in his shoulder subsided. He is convinced that the vitamin D made a difference in the quality of his life.

Clinical trials now underway may answer the question about the benefits of extra vitamin D. Until then, people need to monitor their own levels so they can stay healthy.

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  1. Leslie

    I am so excited with this article. A woman at work cut this out of our local paper and gave it to me to read. I put up a health wall in our work break room each month a different topic, letting others know they have a choice in there health care. January was on VIT D… The more I investigated Vitamin D the more I saw the word inflammation.
    In 2008 I was diagnosed with Osteoarthritis. I have done lots of research in the alternative field, along with being on some prescription pain meds. Due to finances, I had to step away from pain management although in quite a bit of pain. I have continued to feel bad, like the tin man, like I had no life left, always in pain, like my bones dried up like overcooked chicken. Amy way, I had been taking 2000 of Vit d, but I was taking it in the am. Then I upped it to two a day, one in the am one in the PM. The more I read the more I am curious. If I’m going to see a result, it will be in the morning when getting out of bed is very dramatic as per stiffness and pain.
    Well, I am so excited to report, I took 4000iu of Vit D at bed time, now for a week, and I have 99% mobility, and 99% flexibility. I have clarity of mind back again. Today, I go to a new doctor, I’m going to get my 25-hydroxy Vitamin D tested and see where I stand. I often wondered why I felt so good on a sunny day in the summer. It was the natural VIT d I was getting. I get no sunshine in the winter that would manufacture this. Any way, I am excited about this information, I hope you are too.

  2. fbl

    My D level has always been low when tested. My Dr. first had me do sun baths and they made NO difference; then he had me taking vitamin D, and increasing, and increasing. My level finally got up to 40 when I was diagnosed with cervical cancer three years ago.
    I had not had a cold or flu since ’85 even with low D. After my cancer diagnoses my Dr. wanted my level up to 100. No, I’m not there yet but getting close. I’m up to six 5,000 iu caplets a day now. I’ll get tested again in a few months.
    The message here is one MUST get tested. Every body is different. My son got tested too and his was low as well, even with running out in the sun every day.

  3. Donnie

    I was taking 400 IU of D3 a day, as well as getting some sunshine. My lab test showed that I was still quite low, so the dose of Vitamin D3 was increased to 2000 IU. That brought my numbers up to a good level.

  4. cmw

    In your article, you state doctors are debating how much Vit D is needed and what is the “optimal blood level.” Your article further advises to take enough to reach an “appropriate level.” It would be most helpful if you gave us readers some idea of what is generally thought to be a therapeutic level. Vit D is a fat-soluble vitamin so my logic tells me there should be some concern about getting too much from a supplement. I’ve read that one cannot get too much Vit D from the sun.
    People’s Pharmacy response: The usually accepted level for 25-hydroxyvitamin D is between 30 and 80 nanograms/ml.

  5. LJ

    I have been taking a vitamin D supplement for the past 20 years and feel confident that it contributes to my well being at the age of 82, agile, active and pain free.

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